There’s nothing wrong with feeling bummed out from time to time. Everyone does. It’s a natural part of being human, especially when you’re pushing into your teen years. But how can you tell if you’re just down in the dumps or truly livin’ a world of depression?

No doubt about it, it’s not easy being blue. But consider for a second what life would be like if you never had the lows that make you appreciate the highs. Your so-called best bed asks your longtime crush out, and he says yes, and you feel…cheerful? You bomb that surprise quiz in biology…and think, “Gee, this will really help my average”? We don’t think so! But how do you know when you (or a bud) is not just having a big bummer of the week—but honestly depressed? Here’s a few answers to your questions to clear up the confusion.

When I’m feeling lousy and crying for no reason at all, how can I tell if it’s because of depression or just PMS?

Hey, hormones are chemicals. And during puberty, your body’s hormones are constantly, increasing, decreasing or just plain doing whatever they feel like. But all of this affects your emotions.

Each month, before you get your period, the number of hormones in your body increases, causing you to be more emotional than usual. But even when you’re not having your period, those chemicals are still doing the mambo. Given all the changes that are going on, it’s no wonder girls feel moody, irritable and lonely. One minute you’re sobbing enough to fill your sister’s kiddie pool and laughing like a hyena the next. This isn’t depression—it’s normal.

Bottom line? Don’t worry too much if you feel like you’re riding the emotional equivalent of Space Mountain.

I only get bummed on weekends, when I should be having fun. What’s wrong with me?

Take solace in knowing that it is not at all uncommon for teens to feel crummy on Sundays.

Why Sundays? Think about how you usually feel on Fridays. The weekend is coming…no school, fun stuff to do, and you can sleep in! You’re psyched, right? Some people see Sundays in just the opposite way. Sundays marks the end of the weekend—the party’s over. Ugh.

You can also get bummed around the end of summer vacay or the end of a holiday. While people like to joke about school being a drag, it helps your mood to change your overall outlook on your week. Don’t just live for the weekends. Start looking forward to the special things that each day brings—even if it’s just a compliment from the tennis coach on your serve or tater tots at lunch.

The seasons and the weather also contribute to your mood. Now that it’s late fall, the sky is gray and everything looks dead. You’ve got to stay inside, so that means you can’t even enjoy what little sunlight there is. Near the center of the brain is a glad that is affected by light. Researchers believe that significant decreases in sunlight can lead you to feel down and dreary, just like the weather! Make it a point to walk outside and soak up what little sun there is.

What is the deal with depression? Does being stressed mean I’m depressed?

Depression can happen to the most popular girl in school. Some depressed girl appear smart, pretty and confident on the surface, only dealing with their real feelings once they are alone. Depression isn’t picky. Anyone can become depressed—millions of teens suffer from this disease. It’s also possible that just like you inherited your dad’s dimples, you may have a gene that makes you more depression-prone.

But how you cope with life’s hard knocks plays a part, too. Sometimes, stuff happens that you have little or no control over. Potential traumas include Fluffy getting hit by a car, your folks filing for the big D, changing schools, moving to a new home, being teased, finding out your crush doesn’t dig you and fighting with a friend…just to name a few. Any type of unwelcome change in your life can stress you out. (But being stressed doesn’t mean you’re depressed.)

While you can’t control certain bad things from happening, you can control how you deal. Take Tanya. Tanya tries out for the soccer team but doesn’t make the cut. Should she a) let herself feel bummed for awhile; talk about her emotions, fight negative thoughts like, “I’m not good at anything” and make a decision to join a ceramics class instead?

Make it known that I am very available and dying to go, and hope you crush picks up on the cluesWalk up to my crush and ask him to be my date. I’m not just gonna sit around and wait for Prince CharmingMy BFF and I have vowed to be each other's dates to spare us the embarrassment of not getting askedYou won't see me attending any dances with these two left feet!